1. Technical Field
The present invention relates to an electro-optic device provided with an element substrate on which a reflective pixel electrode is formed, and a projection-type display apparatus provided with the electro-optic device.
2. Related Art
In electro-optic devices such as a liquid crystal device, an organic electroluminescence display device, and a plasma display device, an element substrate provided with a pixel transistor, an interlayer insulating film, and a pixel electrode in this order on one side of a substrate body is used. For example, the element substrate used in a reflection-type liquid crystal device of the electro-optic devices is provided with a pixel transistor, an interlayer insulating film, a reflective pixel electrode such as an aluminum film, and an alignment film in this order on one side of a substrate body (see JP-A-2010-139862).
In the liquid crystal device, an insulating film formed of a silicon oxide film or a silicon nitride film may be formed on the surface of the reflective pixel electrode. For example, when a rhombic vapor-deposited film such as a silicon oxide film is used as the alignment film, a planarized insulating film formed of a silicon oxide film or a silicon nitride film is formed as an insulating film on the surface of the reflective pixel electrode.
However, after the insulating film is formed on the upper layer side of the pixel electrode after forming the reflective pixel electrode, significant thermal stress occurs on the pixel electrode due to heat generated when forming the insulating film, there is a problem in that the thermal stress may cause a defect, such as hillock on the surface of the pixel electrode. For example, when an insulating film is formed in a state where a pixel electrode formed of an aluminum film is formed on the upper layer of an interlayer insulating film formed of a non-doped silicon oxide film, a difference between the thermal expansion coefficient (23.1×10−6/° C.) of the aluminum film and the thermal expansion coefficient (0.5×10−6/° C.) of the non-doped silicon oxide film is large, and thus significant thermal stress occurs in the pixel electrode. As a result, a defect such as hillock occurs on the surface of the pixel electrode by thermal stress, smoothness of the surface of the pixel electrode decreases, and the reflectance of the pixel electrode decreases.